With JExcel PRO, you can make simple calculations / relations between the columns.

To create a calculated column click the icon  of any column (1) and select this option (2).

After clicking on it, you will see a dialog where you can

• add a name for this column (1)
• set up a formula for this column:
  • add values (2) or refer to an already existing column (3)
  • set relations between these values (4) 
    • relations you can choose from: +, -. x, /
  • Click on 'Create" (5)

After clicking on "Create", you will see the column created:

You can always change the formula of it by clicking here (2).

Or delete the whole column by clicking here (3).